OK three games i looked at were pac man, sonic and halo, they were quite different i can tell you that much. Pac man every one has at least seen it very simple your in a maze of sorts, so the level design is simple in that sense. You can see the whole stage area and you just roam it doing what needs to be done. Sonic compared to pac man is quite advanced, it a very fast side scrolling game. The stage is designed very linear to take advantage of the speed the game could move at, this such as gravity and speed meant the levels had more obstacles for the designers to play with such as holes, jumps and loops. Halo is obviously a FPS so the level is designed like most shooters to have cover and places to hide from fire and also has big open spaces for where vehicles are used.